The Analytical Microscopy Core has been in operation at Hospital for Special Surgery since 1992, and has been at resource for the Hospital's research staff, providing the following services: transmission and scanning electron microscopy, light microscopy, embedding and sectioning calcified tissues, histochemistry, immunocytochemistry, image analysis and morphometric methods. The major objectives of this core are: (1) to provide morphological techniques for the research staff at the Hospital, necessary for them to carry out their particular projects; (2) to provide training where appropriate and to provide investigators with options to utilize current techniques; (3) to continue to develop new applications for study of calcified tissues. We are in the process of developing in situ hybridization techniques to apply to calcified tissues, which is an example of new methodology and new applications being developed by the core for the research staff. This core is now poised to join with the two new research cores (Infrared Imaging and Mechanical Testing) to form the Core Center for Skeletal Integrity, which will provide a larger resource base for the collaborative research that is developing within the research community of the Hospital and its affiliate institutions.